Powering LCD (non standard leads?)

RickSeymour · 07-26-2005, 07:06 AM

Hello,
I have just recieved a 7" LCD screen (£40 on ebay!) and would like to know how to apply power to it. I am planning to run my ITX system off 12V batteries (separate from the cars own battery) I have attached photos of the monitor and cables.

What would the best way be to power the device to maximise the lifespan of the LCD?

Do i have to use Voltage regulation? Bear in mind that this circuit is not under the problems of engine crank etc

Can i connect a monitor and Motherboard on the same battery (although looking below at the value of 8Ahr, I think i'm going to need something with a bit more!

The 12V battery I have is a Lead Acid HondaYYuasa motorcyle battery (YTZ10S)
12V = 8Ahr
Recharge =
0.9A =5hr
4.5A (Quick) = 1 hr
Is this a good battery to use, what other recommendations do people have!?
Reason for using a separate battery is that the car is drive (Honda Civic 04) is a company car, and altering the wiring would invalidate ... well.. i'd get shot!

Many Thanks

Rick Seymour
Lancashire UK

mox · 07-26-2005, 07:53 AM

A direct connection to the PC's 12V rail is considered by many to be the best way to power a (12V) TFT screen. Assuming that you will be using a power supply like an Opus or an M1-ATX, this will ensure constant brightness of the backlight as well as auto power on/off. What's wrong with using the car's cigarette lighter btw..?

Chech out the FAQ section and/or the sticky in this LCD/Display forum.

RickSeymour · 07-26-2005, 08:37 AM

When you say the 12V rail.... does that mean the 12V output from a PSU?
So.. could i get an old ATX .. strip the wires off the HD/Floppy and connect them to the red and black of the monitor cables
On a HD/Floppy cable there (L to R) Red 2 Blacks and a Yellow
which should i connect to which on the monitor
(Basic stuff i know... but best to be safe and ask)
Thanks

drunk_zx · 07-26-2005, 09:07 AM

Yes, from the psu the molex connectors used to connect the harddrive/cd-rom is simple. The yellow wire is +12V DC and the black next to it is its ground.

red blk blk ylw
| o o o o |
+5v gnd gnd +12v

Theres a small visual just incase. Also there is a thread on here somewhere that tells you how to power up the ATX PSU with no motherboard, Ive done it and it works well if you have a psu with the off/on switch on the back. There only one green cord on the psu's mobo hookup and all you have to do is ground it to one of the ground wires on the psu's mobo connection. Its around here somewhere.

RickSeymour · 07-26-2005, 09:12 AM

I've got a crappy old motherboard too that i dont mind burning out

On the photo above... can i just confirm.. black to black... red to yellow?
By the way... why are there 2 red connectors on the monitor?

PS loved the diagram!

EsKALad · 07-26-2005, 11:28 AM

why add a carputer to a company car. the whole point of car computers is to be different and custom. now if you mess with the wiring you said youll get shot? lol haha do you think your 12v battery will power your computer for how long if there is nothing recharging it?

drunk_zx · 07-26-2005, 12:06 PM

Quote: Originally Posted by RickSeymour

I've got a crappy old motherboard too that i dont mind burning out

On the photo above... can i just confirm.. black to black... red to yellow?
By the way... why are there 2 red connectors on the monitor?

PS loved the diagram!

Well on the molex the red wire is a +5v DC the black wire directly next to it, is its 5v gnd, the black wire directly next to that black one is the 12v gnd, and the yellow wire next to that black one is the +12v dc.

And 2 red connectors on the monitor, by that i assume 2 red wires coming from the lcd, one of them is a direct +12vdc(possitive) and the other should be on for a switch(ACC switch like when you hit your accesory on your ignition switch.)

HU(cd decks) use the same thing, one is basically a always on positive to keep memory stored or for other reasons, the other wire is usually the ignition switch to know when to turn the deck on(I.E. when you put you key in and start the car)

Hope this helps.